Large buildings, especially warehouses or other such buildings having large wall and ceiling expanses, often make use of walls or ceilings constructed on location. These walls may be made from concrete block. However, such concrete block walls are time consuming to build and are highly labor intensive. To speed construction and lower costs, the walls may be constructed of reinforced concrete which is poured directly in the place where a wall is desired. However, such walls generally may only be poured to controlled heights and widths and require the use of expensive forming methods. Further, to insulate concrete block walls and poured in place walls, it is necessary to apply the insulation to the interior of the wall and to then frame around the insulation to form an interior wall which maintains the insulation in place while at the same time protecting the insulation and hiding it from general view.
To speed construction and lower costs, builders have resorted to walls which are poured flat on the ground, either on-site or at offsite locations. Likewise, concrete ceiling panels may be poured at ground level either on-site or at manufacturing facilities. These ceiling and wall panels are then lifted or tilted into place.
As energy costs have risen and the costs to heat and/or cool buildings has increased, the need to insulate buildings has increased dramatically. The principal solution to this need to insulate large wall and ceiling expanses in an esthetic manner has been the development of manufacturing wall sections in several plies. The lamination, or amalgamation of wythes or layers, generally consists of an outer non-structural concrete layer of minimal thickness next to which is placed an insulating board of the desired thermal barrier thickness. This lamination is then completed by the addition of a final concrete layer which is generally much thicker and steel reinforced. The added final ply thickness is the element that supports the wall section and incorporates it into the intended structure. To prohibit delamination, the several wythes or layers must somehow be fastened together into a solid immobile unit.
Previously, the fasteners used to connect the three layers have been rudimentary requiring intensive manual labor for insertion or use. Currently available commercial products require specially prepared insulating board materials that must be used in conjunction with their devices which are pre-drilled or pre-formed with the necessary holes through which the prior art connectors are inserted. Generally, the connectors and pre-holed insulation panels are sold by a common manufacturer which limits the user to a single source, generally higher priced, supplier.
The manufacture of such a wall typically is performed on a horizontal casting bed, some other firm flat surface, or the concrete floor of the building it is intended to be part of. The first operation is to cast a thin layer, or concrete wythe, of the panel within the containing formwork. While the concrete is still wet and in a soft plastic state an insulating board which has prearranged holes spaced in repeating order is quickly placed over the wet concrete. Construction workers then proceed to insert the prior-art connecting devices through the holes in the insulating board and into the lower concrete layer while leaving a portion of the connector standing above the insulating board.
The insertion of the prior art connectors requires much manipulation and working by the workers because of the connector""s construction. Further, after insertion, it is generally considered necessary for the workers to return to each inserted connector and to manually hand rotate 90xc2x0, after full insertion through the insulation board, each connector. The purpose of the rotation is to embed the connector in the wet concrete below. The consistency of insertion is impaired by the inevitable variations that occur when the workers repeat this operation thousands of times for a given number of wall panels in a building. The human factor alone contributes to inconsistent results. To make embedment fully effective most all current systems compound the potential for variation of results by recommending that the workers walk over the entire surface of the insulating board. This is done to force the wet concrete into recesses in the connecting devices for fuller envelopment of the connector stem in the wet concrete.
A connector is provided for use in forming a three ply concrete-insulation-concrete panel. The connector comprises a generally rod-shaped member having at least one angular fin extending from the rod causing the connector to rotate during insertion of the connector into the insulation layer and the first concrete layer. The connector preferably is generally rod shaped and includes three distinct segments. The first segment includes a pointed terminal end. Preferably, the first segment further includes two of angular fins spaced on opposite sides of the first segment. Even more preferably, the first segment includes four angular fins spaced about the circumference of the first segment.
The first segment further preferably includes at least one flat area spaced approximately 90xc2x0 around the exterior circumference of said first segment from one of the fins. The connector also preferably further includes at least one flat area spaced approximately 270xc2x0 around the exterior circumference of the first segment from one of said fins. More preferably, the at least one flat area spaced approximately 270xc2x0 around the exterior circumference of the first segment from one of the fins comprises two flat acutely shaped triangular areas.
A connector is also provided for use in forming a three ply concrete-insulation-concrete panel where the connector is formed of glass filled nylon. The connector includes a first pointed end having sufficient sharpness to permit perforation of insulation board without the separation and displacement of an insulation plug.
A connector is also provided for use in forming a three ply concrete-insulation-concrete panel which comprises a generally rod-shaped member having a first end forming a sharpened point, a first body segment including four circumferentially spaced angled fins, a second body segment including at least two circumferentially spaced angled fins, and a third body segment having at least two circumferentially spaced flat segments. The connector preferably includes four circumferentially spaced angled fins on the second body segment and the connector is preferably formed from glass filled nylon.
A method of forming a multiply ceiling or wall panel is also provided. In the method, a first concrete face ply is poured at grade level. Unperforated insulation board is arranged on the uncured first concrete face ply in any desired arrangement. The insulation board is then perforated with a connector which passes through the insulation board and into the first concrete face ply such that a portion of the connector extends above the surface of the insulation board. A second concrete structural ply is then poured over the insulation board to engage the connector. In practicing this method, preferably, the connector comprises a generally rod-shaped member having at least one angular fin extending from the rod causing the connector to rotate during insertion of the connector into the insulation layer and the first concrete layer. The generally rod shaped member preferably includes three distinct segments of which the first segment of includes at least two angular fins, and more preferably four angular fins, evenly spaced about the first segment.
Preferably, in practicing the method, the connector is inserted into the insulation board using an insertion tool which releasably maintains the connector in an insertion position.
An insertion tool for inserting a connector into an unperforated insulation board is also provided. The insertion tool comprises a handle, a barrel, and a tubular holder for holding the connector in a releasable position. The insertion tool tubular holder preferably includes means for maintaining the connector within the insertion tool until release is desired. Preferably, the means for maintaining the connector within the insertion tool until release is desired comprises a spring. Also preferably, the insertion tool barrel is of sufficient length to permit insertion of the connector by a man in a standing position.